“When we look at young red dwarfs in our galaxy, we see they’re much less luminous than our Sun today,” said lead author Vladimir Airapetian, also from NASA Goddard, in the statement. “By the classical definition, the habitable zone around red dwarfs must be 10 to 20 times closer-in than Earth is to the Sun. Now we know these red dwarf stars generate a lot of X-ray and extreme ultraviolet emissions at the habitable zones of exoplanets through frequent flares and stellar storms.”
This has implications for worlds like Proxima b, a supposedly Earth-like planet orbiting around our nearest star, the red dwarf Proxima Centauri. Airapetian and his team suggest it is hit by intense radiation from superflares almost every two hours, meaning it would have lost its oxygen in just 10 million years.
More and more, it's looking like our Sun is a rather nice star to orbit.